Android: Sleep Timer will automatically pause the media player on your Android phone after a set period of time so you can go to sleep listening to music or a podcast without fear you'll wake up to a dead battery and an empty playlist.

Many Android media players have their own sleep timers, but Sleep Timer gives you control over all of them, including players that don't have their own. Set the timer and select the app Sleep Timer should stop, and the app will sit in the background until the time comes to stop the audio or video player. Best of all, it's completelty free.